Propeller



Feb. 2, 1932. c. B. DAWE 1,843,481

PROPELLER Filed Sept. 10, 1928 INVENTOR. (x/72m? 542: flflwa.

ATTORNEY tented Feb. 2, 1932 i NITE'D STATES CHARLES BALE DA TNE, OF BERKELEY, CALIFORNIA PROPELLER Application filed September 10, 1928. Serial No.'804,892.

The invention forming the subject matter of this application relates to propellers.

The primary object of the invention is the provision of a propeller which is formed by two helical blades oppositely disposed on a hub, each blade extending from end to, end of the hub, the blades being formed so as to rovide concave propelling surfaces formed in substantially half turned spirals, directly opposite each other, the extremities or outer edges of each blade describing substantially a semi-circle.

Another object of the invention is the provision of a propeller having two helical blades oppositely disposed on a hub, which blades are integral with the hub; the curvilinear entering edge of each blade extending radially from one end of the hub, while the similarly curvilinear trailing edge extends radially from the other end of the hub at substantially a half a turn from the entering edge. The blade, between the entering edge and the trailing edge, forms a propelling surface in a substantially half-turn spiral, the spirals of the opposite blades being formed directly opposite each other and being so disposed that the extremities or outer edges of the blades describe a complete circle. The said propelling surfaces are formed by the concave spiral surface of each blade.

Otherobjects of the invention are to provide a propeller of the character described that will be superior in point of simplicity, inexpensiveness of construction, positiveness of operation, and facility and convenience in use, and general efficiency.

In this specification and the annexed drawings, the invention is illustrated in the form considered to be the best, but it is to be understood that the invention is not limited to such form because it may be embodied in other forms; and it is also to be understood that in and by the claims, following the description, it is desired to cover the invention in whatsoever form it may be embodied.

In the accompanying drawings .Figure 1 is an end view of the propeller, looking at the front end thereof; and

Figure 2 is a bottom plan view of the propellet.

Referring to the accompanying drawings, where nsimilar reference characters designate similar parts thruout,the various figures described above adequately illustrate my invention, and the following detailed descrip-' tion is commensurate with the above mentioned drawings in enabling an artisan to construct and assemble the constituent parts of the same.- a

' In carrying out my invention, I make use of the propeller in connection with pumps or other similar device, in which a fluid is lifted thru a conduit by means of a rotating element. When the propeller is used in such connection, it is enclosed in a suitable conduit, not shown, the propeller being so designed that it transmits the power of an engine to the fluid with high efiiciency in the aforesaid devices as an impeller; and it also functions with a high elficiency, if used as a propeller in. connection with boats .or the like, in which latter case, there is no conduit or pump casing provided to surround the propeller, but the propeller is driven outside of the vessel in the usual manner.

The propeller is of a unitary character and comprises a hub 5 from which extend blades 6 and 7, opposite to each other, said blades being integral with the hub 5. The blades 6 and 7 are helical. The helical blade 6 has a curvilinear entering edge 8 extending radially from the front end of the hub 5.

A trailing edge 9 of the blade 6 is curvilinear similarly to the entering edge 8 and extends radially from the rear end of the hub 5 and at an angle slightly less than 180 from the entering edge v8. The surfaces of the blade 6, which thrusts on the water, is formed between the entering edge 8 and the trailing edge 9 in a substantially half-turn spiral, extending from the front to the rear end of the hub, and from the inner to the outer extremities of the blade 6. The outer extremity or outer edge of the blade 6 forms an arc of a circle concentric with the hub 5. This arcuate outer edge is designated by the numeral 11. The inner or thrust surface'of the blade 6 is formed so as to have the same concavity as that of the entering edge 8, while the outer face of the blade 6 is formed so as to conform 2 aseaeei to the convex curvatures of the entering and trailin edges 8 and 9. The thrust surfacea of the lades are designated by the numeral 12, while the trailing surfaces are designated by the numeral 13.

The other blade 7 has an entering ed e 14 of the same curvature as the entering edge 8 and is disposed oppositely to the entering edge 8, as 1s clearly shown in Figure 1. The trailing edge, denoted by the numeral 16, terminates the blade 7 at the rear end of the hub 5 and the trailing edge 16 extends oppositely to the trailing edge 9 and has the same *curvature in the opposite direction. The

blade 7 is formed in a substantially half-turn spiral from the entering edge 14 to the trailing edge 16 around the hub 5. In short, the blade 7 is formed of an identical shape with the blade 6, excepting that the half-turn spirals of the opposite blades are formed directly opposite each other. If the spirals were fully half turned, and the respective entering and trailing edges were exactly 180 apart, the outer edges 11 of the blades 6 and 7 would describe a complete circle concentric with the hub 5.

The hub 5 is provided with an axial central opening 17 into which extends a driving shaft 18 in the usual manner. In operation, the rotation of the driving shaft 18 in a clockwise direction, viewing Figure 1, results in a thrust exerted upon the fluid by the impelling orpropelling surfaces 12. The blades 6 and 7 thus work simultaneously in the fluid. The particular spiral shape of the vanes or blades of the propeller render the same highly efficient, both in use thereof as impeller blades or propeller blades. The thickness of each blade is gradually reduced from the hub toward the outer extremities of the blade. The propeller is referably of a unitary character, and it combines facility of construction and accuracy, with a ruggedness of construc! tion and. positiveness of operation, especially adapting it for its use.

1 claim:

"1. A propeller com rising a pair of diametrically disposed spiral blades, said blades having a concave reaction surface, beginning with a tangent to thehub and ending at the tip of the blade.

2. A propeller comprising a pair of spiral blades, diametrically disposed, each having an included angle related to the axis of apf proximately one hundred and thirty-five degrees, said blades having a concave reaction surface as radially related to the axis a hub for said blades a bore through said hub, said concave reaction surface terminating at the tip of the blade and being a continuation of a tangent to the periphery of the hub.

In testimon whereof I a my si ature.

HARLES BALE 10 WE. 

